Too Screwed or Not Too Screwed (that is the question)

I am building my first computer for myself in the upcoming month. I have built other brand new computers for the company I work for, so I have a general idea of how to go about doing this. My issue is this:

I bought a case about 2 years ago, a Nikao Kitty case (I'm a girl, it's a cute case) and have been dying to build the thing since I got the case. Problem is, I moved and in the move, I lost the screws and standoffs that came with the case. Normally, I wouldn't think this a problem as I have literally boxes of screws and standoffs from other computers because you always get too many. The thing is, this case has bizarre (I haven't seen them before) openings instead of standard tiny holes. They have squares. They are about .35 inches square.

I found in my shop some metal things that are the right size for these holes. They have screw holes on the top. They do not have anything on the bottom to hold them in.

Basically, I'm asking if anyone knows what I need to attach a motherboard to this case. If anyone could point me in the direction of a link with directions, or a place to buy a screw set containing what I need... that would be useful, too. I am almost ready to buy another case as I know they redesigned it (and subsequently discontinued it) but it would come with new screws, probably the nicer ones with the screw in standoffs.

Any help would be appreciated. I want to play Temple of Elemental Evil.

If the "metal things that are the right size for these holes" are what i think they are then you just have to push them through the square holes from the outside. After you hear a snap they will hold themselvs still perfectly and you can use normal screws to attach the motherboard.

Since the tops of the metal standoffs are quite big, make sure they align perfectly with the motherboard's mount holes so you won't short out any wires.

There are also plastic standoffs for those square holes. that you have to push in from the inside.

The standoffs that I have don't seem to snap in anywhere. They just sort of sit there. They are thin metal, and look a bit like tents with a hole on top. I wish I could take a picture of them and post it but I lent my digital camera to someone. Grrr. When I put them in the hole in the case they just fall out.

You may have to bend the legs out a little bit. When you look closely at the base of those "tent-legs" you should see some sharp edges on either side of those legs, pointing outwards.
These "snap in" when you push them properly into your PC-frame from underneath.